In a wound body formed by winding a band-shaped sheet member such as an electrode of a lithium ion battery and a film capacitor, it is important to inspect winding deviation of the sheet member because of the characteristics thereof. As a device for inspecting winding deviation, a device as illustrated in FIG. 10 is described in Patent Literature 1 as conventional art.
In FIG. 10, an inspection object 2 is placed on a table 1. The inspection object 2 is a wound body in which the winding of a sheet member has been completed. X-rays are applied to one side face of the inspection object 2 placed on the table 1 from an X-ray applicator 3. A TV camera 4 images the other side face of the inspection object 2. An X-ray transmission image of the inspection object 2 is obtained by the imaging using the TV camera 4. The winding deviation of the inspection object 2 is inspected on the basis of the X-ray transmission image in the conventional art.